I don't know if this will help but here goes...
Last week, just out of curiosity, I called around to places I found in the yellow pages under pizza-wholesale/restaraunt supplies and found that most weren't receptive to a private individual just stopping by to buy small quantities of flour, tomato product or cheeses. After being persistent in my search, I found one place that supplies many local pizzerias that also does a small "cash and carry" business. Wooot! They have Stanislaus, which was really surprising. I also found our local gourmet shop has grande cheese. So now my pizza making should get kicked up a notch.
So if you haven't been able to find the pro quality items, just let your fingers do the walking and call every place you can find and ask if they do "cash and carry".